顶空毛细管柱气相色谱法测定生活饮用水中的三卤甲烷

Determination of Trihalomethane in Drinking Water by Head-Space Capillary Column Gas Chromatography

目的:建立顶空毛细管柱气相色谱法测定生活饮用水中三氯甲烷(Trichloromethane,TCM)、二氯一溴甲烷(Bromodichloromethane,BDCM)、一氯二溴甲烷(Dibromochloromethane,DBCM)和三溴甲烷(Tribromomethane,TBM)4种三卤甲烷(Trihalomethanes,THMs)含量的方法。方法:将密封且已加入水样的顶空瓶放入全自动顶空仪中,加热到设定温度,使饮用水中的4种THMs在气液两相中实现动态平衡,气体进入气相色谱仪经色谱柱分离后,进入电子捕获检测器检测,外标法定量。结果:TCM、BDCM、DBCM及TBM在各自浓度范围内线性关系良好,相关系数R≥0.999;方法检出限为0.00598~0.0227μg·L^(-1),回收率在72.3%~119.2%,相对标准偏差为1.7%~3.9%。结论:该方法操作便捷、结果准确可靠,适用于生活饮用水中三卤甲烷含量的测定。

Objective:To establish a head-space capillary column gas chromatography method for the determination of four kinds of trihalomethanes(THMs)in drinking water,including trichloromethane(TCM),bromodichloromethane(BDCM),dibromochloromethane(DBCM)and tribromomethane(TBM).Method:The sealed headspace bottle with added water sample was put into an automatic headspace analyzer,and heated to a set temperature,so that four kinds of THMs in drinking water could be dynamically balanced in gas-liquid two phases.The gas entered a gas chromatograph,separated by a chromatographic column,detected by an electron capture detector,and quantified by an external standard method.Result:TCM,BDCM,DBCM and TBM had a good linear relationship in each concentration range,with the correlation coefficient R≥0.999;the detection limit of the method is 0.00598~0.0227μg·L^(-1),the recovery rate is 72.3%~119.2%,and the relative standard deviation is 1.7%~3.9%.Conclusion:The method is convenient,accurate and reliable,and suitable for the determination of trihalomethanes in drinking water.